As Spain developed new colonial territories, new deposits of silver were found. This silver needed to be quickly exported back to Spain. Starting in the time of Philip II, irregular coinage was produced. This coinage was called Cobs.

In order to make round coins, a bar of silver must be rolled out into a sheet with a specific thickness. There was no time for this, so another method was developed. Silver bars were cut into chunks with the same exact weight. Each cob would weigh the same, but be totally different in size and thickness.

The Spanish Silver cob derives its name from the Spanish word, "cabo" which means "the end", and refers to the piece of silver clipped off the end of the silver bar.

Many of these coins had cracks and were highly irregular in shape, but every coin weighed exactly the same.

Images were pressed on each cob, but due to their irregularity, oftentimes only a portion of the image would be struck onto the silver piece.

If the cob came in overweight after the initial clipping, another clipping was done, which made the coin even that more disfigured.

These mass-produced coins were prevalent from 1572 through 1773, and came in a number of denominations under separate rulers of those times.

Authenticating a Spanish cob can be difficult. Particular details on images of the coins can be attributed to specific kings during specific periods. Also, specific details are attributable to specific mints. For example a Jerusalem cross with a ball of each extremity indicates the Silver cob was minted in Mexico.

Because of the irregularity of these coins, forgeries and coin clipping were prevalent.

Still though, Spanish Silver cobs can be authenticated and fun to collect.